1. Field of the Invention
This invention relates to pumps and more particularly to a sonic pressure wave operated pump having a rotary sonic pressure wave generator.
2. Description of the Prior Art
The most commonly used liquid pumping mechanism includes an electrically, or otherwise, powered motor which drives a shaft, commonly referred to as "sucker rods", which extend from the motor at ground level downwardly through a well casing to drive a down hole pumping device. Such pumps are costly, expensive to install and maintain and are expensive to operate.
In attempts to reduce the costs associated with the above described type of prior art pump, and other well known pumps, another basic type of pumping mechanism has been suggested. This suggested pumping mechanism includes a reciprocally operated piston structure for imparting an intermittent pressure wave on a column of liquid contained in pump tubing which extends from the subterranean source of the liquid to an above ground location. In general, the pressure waves are generated by an above ground mechanism, which reciprocally impacts the column of liquid and, in addition, will cyclically open and close a liquid delivery port. Such impacting of the column of liquid produces pressure waves that are transmitted by the liquid to the down hole pumping device, such as a standing valve, to impart a reciprocal movement thereto. The down hole pumping device usually includes a plunger, or similar mechanism, which is biased upwardly by suitable springs and has a central passage formed axially therethrough with a one-way check valve located in the passage. When the hydraulic pressure waves move the plunger down against the spring bias, the check valve opens to admit the liquid being pumped into the passage. And, the subsequent upstroke of the plunger closes the check valve and causes a general upward movement of the liquid column with the uppermost portion thereof discharging an amount of liquid through the delivery port, with the delivered amount being equal to the amount taken in by the down hole pumping device.
Examples of pumping mechanisms which operate generally in the above described manner are fully disclosed in U.S. Pat. Nos. 2,379,539; 2,355,618; 2,428,460; 2,572,977; 2,751,848 and 3,277,381.
These prior art pumps critically depend on ideal adjustments of the input frequency relative to the length of the pump tubing in which the liquid column is contained. That is, resonant timing. Further, these prior art pumps are seriously limited as to their pumping capacity due to fluid friction, inertia of the liquid, and the like. The problems with resonant timing, frictional losses, and the like, have kept these prior art pumps from achieving any significant degree of commercial success.
Therefore, a need exists for a new and improved pumping mechanism which overcomes some of the problems and shortcomings of the prior art.